api: rename performMigrations to migrate

api/database_migrate.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+func migrate() error {
+	return migrateFromDir(os.Getenv("STATIC") + "/db")
+}
+
+func migrateFromDir(dir string) error {
+	files, err := ioutil.ReadDir(dir)
+	if err != nil {
+		logger.Errorf("cannot read directory for migrations: %v", err)
+		return err
+	}
+
+	statement := `
+    SELECT filename
+    FROM migrations;
+  `
+	rows, err := db.Query(statement)
+	if err != nil {
+		logger.Errorf("cannot query migrations: %v", err)
+		return err
+	}
+
+	defer rows.Close()
+
+	filenames := make(map[string]bool)
+	for rows.Next() {
+		var filename string
+		if err = rows.Scan(&filename); err != nil {
+			logger.Errorf("cannot scan filename: %v", err)
+			return err
+		}
+
+		filenames[filename] = true
+	}
+
+	logger.Infof("%d migrations already installed, looking for more", len(filenames))
+
+	completed := 0
+	for _, file := range files {
+		if strings.HasSuffix(file.Name(), ".sql") {
+			if !filenames[file.Name()] {
+				f := dir + string(os.PathSeparator) + file.Name()
+				contents, err := ioutil.ReadFile(f)
+				if err != nil {
+					logger.Errorf("cannot read file %s: %v", file.Name(), err)
+					return err
+				}
+
+				if _, err = db.Exec(string(contents)); err != nil {
+					logger.Errorf("cannot execute the SQL in %s: %v", f, err)
+					return err
+				}
+
+				statement = `
+          INSERT INTO
+          migrations (filename)
+          VALUES     ($1      );
+        `
+				_, err = db.Exec(statement, file.Name())
+				if err != nil {
+					logger.Errorf("cannot insert filename into the migrations table: %v", err)
+					return err
+				}
+
+				completed++
+			}
+		}
+	}
+
+	if completed > 0 {
+		logger.Infof("%d new migrations completed (%d total)", completed, len(filenames)+completed)
+	} else {
+		logger.Infof("none found")
+	}
+
+	return nil
+}